During underground mining, it is a requirement for purposes of safety as well as federal law to install support to the roof of a passage at various intervals. This is often done using a mining machine known in the vernacular as a “roof bolter.” Typically, such a roof bolter is capable of both forming (drilling) boreholes and then installing roof anchors or “bolts” in the boreholes.
Bolters often include an elongated boom for raising and lowering an attached bolting module, which incorporates a drill for forming the borehole for receiving the bolt or anchor. Proper positioning of the drill feed mechanism (commonly called the feed or the drill mast) is critical for full utilization of the entire effective length of the drill steel. In many cases, if the positioning of the drill is proper, then a hole can be drilled with one drill steel. If optimal positioning cannot be reached, then the same task may require two or more different drill steels to drill the hole. Using multiple drill steels can require additional time and handling, which can increase the possibility of injury. Similar issues arise with installation of a bolt. Achieving a better position may result in a single pass installation versus a more time consuming, and possibly more dangerous two-pass installation. In the case of drilling and installation of a bolt, the difficulty can be magnified in tight quarters, such as in narrow seam mining.
Accordingly, a need is identified for a drilling mechanism that allows for a greater range of motion of the drill, that operates with such range of motion within a small space, and that allows for more efficient use of time and space in the drilling and bolting actions. This may include various aspects which allow the drilling mechanism access to a greater degree of the rib, the roof, and the face of the mine, as well as allowing the drill to operate with a more compact design to prevent certain aspects of the drill from interfering with overall operation.